Field of the Invention
The invention relates to a semiconductor process, and particularly relates to a semiconductor process capable of well controlling the removal time of the oxide layer on the epitaxial layer.
Description of Related Art
Currently, an oxide layer formed on an epitaxial layer is removed by using a chemical solution after a doped region is formed in the epitaxial layer by performing the ion implant process. However, the removal time of the oxide layer is not easy to control. If the removal time of the oxide layer is too long, the loss of the epitaxial layer is increased. On the other hand, if the removal time of the oxide layer is too short, oxide layer residue remains on the epitaxial layer, and the contact opening would not expose the epitaxial layer sufficiently.